The present invention relates to a guide for tip to transmission path contact, and more specifically to a guide to facilitate relatively secure contact between an electrical test probe tip and transmission paths of circuit board components on a circuit board.
Typical modern circuit boards tend to include a variety of components (hereinafter referred to generally as “circuit board components”). Most of these circuit board components have leads (e.g. through-hole leads), legs, pins, pin headers, contact headers, or other transmission paths (hereinafter referred to as “transmission paths”) though which electrical signals flow into and out of the circuit board components. These transmission paths may have a variety of shapes and sizes. Circuit board components often need to be monitored or tested by testing instruments such as oscilloscopes and other measuring, monitoring, diagnostic, and signal processing instruments. Other testing instruments may provide stimulus, act as the receiving component, or perhaps even provide some form of correction signal.
Electronic test probes may be used to provide an electrical connection between circuit board components and testing instruments. An electronic test probe generally consists of a probing head, a cable, and a connector. The probing head may have an integral or replaceable probing tip that is suitable for making an electronic contact with electrical components. The probing head is attached to a first end of the cable and the connector is attached to the opposite end of the cable. For purposes of this disclosure, test probe tips having multiple contact mechanisms (such as a differential test probe tip that would have two contact mechanisms) would be described as having at least one tip or as having multiple tips. It should also be noted that the term “tips” is not limited to electronic test probe tips, but may also include alternative types of test probe tips.
A conventional test probe tip is generally in the shape of a cone that narrows, much as a point of a pencil, becoming a sharp point. Differential probe tips have two points of contact. Still other probe tips have more points of contact. Test probe tips are usually made out of conductive metal such as copper, beryllium copper, nickel-palladium alloy, metal alloy, aluminum, steel, or a similar conductive material.
Conventional test probe tips can easily slip off transmission paths of circuit board components, especially pointed, rounded, or irregularly shaped transmission paths. After slipping off a circuit board component transmission path, the exposed conductive material on a conventional test probe tip may, for example, contact two transmission paths at the same time, cause an electrical short, and possibly damage the component.
U.S. Pat. No. 4,055,800 to Fisk et al. is directed to a test clip for electronic chips. The Fisk device is an integral plastic test clip that includes a pair of opposed jaws that are pivotal relative to each other about a junction and that are provided with inner elongated grooves radiating from the junction for the snug reception of the similarly located terminals of the chip and openings through which the clip communicates with the grooves to guide probes into direct contact with selected terminals. There are many problems with the Fisk device. For example, one problem with the Fisk device is that it is relatively complicated to produce because of its complicated shape. Another problem with the Fisk device is that its hinge element can easily break when it is being placed or removed on the chip. Yet another problem with the Fisk device is that different sized clips must be made for each size and shape chip. This could require the user to purchase and store an incredible number of different sized clips. Still another problem is that the Fisk device must contact both sides of the chip because it has to grip both sides. The gripping feature of the Fisk device can also cause problems with bending or breaking the terminals of the chip.
U.S. Pat. No. 4,767,985 to Shearer, Jr., et al. is directed to a claw grip contact probe for testing and diagnosing multi-lead electrical flat packs. The Shearer probe device includes a body and a sliding plate. The sliding plate contains two sets of holes into which are inserted spring-loaded electrical contact probes for making contact with the leads of the flat packs. The body includes comb teeth for orienting the body over the leads of the flat pack, as well as gripping means having hook ends for securely fastening the probe device to the flat pack being tested or diagnosed. The gripping means include an outwardly flared portion against which the sliding plate means exerts inward lateral pressure causing the hook ends to grip underneath the flat pack at each corner thereof to clamp it securely in place. There are many problems with the Shearer device. For example, one problem with the Shearer device is that it is relatively complicated to produce because of its two-part construction as well as the complicated shape of both parts. Another problem with the Shearer device is that its gripping means and hooks can easily break when the Shearer device is being placed or removed on the flat pack. Yet another problem with the Shearer device is that a different sized claw grip must be made for each size and shape flat pack. This could require the user to purchase and store an incredible number of different sized claw grips. Still another problem is that the Shearer device must contact both sides of the flat pack because it has to grip both sides. The gripping feature of the Shearer device can also cause problems with bending or breaking the leads of the flat pack.
U.S. Pat. No. 6,281,695 to Chung, et al. is directed to an integrated circuit package pin indicator that may include probe guides. The Chung indicator includes a top marking plate with indicia for the multiple pins of the IC package. Each pin marker terminates in a hole or slot that is adapted to guide a probe to a selected pin. There are many problems with the Chung indicator. For example, one problem with the Chung indicator is that it must be made for each size and shape IC package. This could require the user to purchase and store an incredible number of different sized indicators. Still another problem is that the Chung indicator contacts all sides of the IC package.
U.S. Pat. No. 5,387,872 to Nightingale is directed to a positioning aid for a hand-held electrical test probe for directly positioning a hand-held electrical test probe onto leads of a surface mounted IC. The Nightingale positioning aid has a housing with a central bore therethrough for receiving the probing tip of the test probe. One end of the housing, which is normal to the central bore, has at least four teeth extending therefrom defining slots for engaging the leads of the IC. The central bore is exposed in the central slot of the housing for exposing the probing tip therein for providing an electrical connection between one of the leads on the IC and the electrical circuitry of the probing head. There are many problems with the Nightingale positioning aid. For example, one problem with the Nightingale positioning aid is that it must be positioned on the IC leads each time it is to be used. Although this feature makes it convenient for probing multiple different IC leads, it is inconvenient if the Nightingale positioning aid must be repositioned each time a particularly relevant IC lead is to be probed. Another problem is that the Nightingale positioning aid is attached to the probing tip and must be removed each time the probing tip is to be used to probe something other than the lead of a surface mounted IC.